Cerebral Blood Flow during Exercise in Heart Failure: Effect of Ventricular Assist Devices

Smith, Kurt J.; Suárez, I.; Scheer, Anna; Chasland, Lauren C.; Thomas, Hannah J.; Correia, Marília de Almeida; Dembo, L.; Naylor, Louise H.; Maiorana, Andrew; Green, Daniel

doi:10.1249/mss.0000000000001904

Cited by 15 publications

(18 citation statements)

References 32 publications

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“…During submaximal exercise (20%-60% V O 2peak ), there is typically a 10%-20% vasodilatory increase in CBF, which is positively correlated with increases in PET CO 2 , MAP, and intra-arterial shear rate (36). We did not observe such increases during exercise in LVAD individuals in our other recent study (37) or in our pretraining LVAD individuals in this study. A novel study by Brassard et al (8) found that, to increase CBF during exercise in untrained LVAD patients with axial-flow pumps, increases in pump speed were required.…”

Section: Discussioncontrasting

confidence: 56%

“…The improved durability of third-generation LVADs and the continuing scarcity of donor organs has led to an increase in the signifies interaction and post-hoc-revealed differences between pretraining (Pre TR) and post-training (Post TR); P Ͻ 0.001. number of LVAD implantations worldwide for "destination therapy" (1). Although functional capacity improves from preimplantation status, recipients of LVADs still experience impaired aerobic capacity and cerebrovascular function during exercise (7,8,37). Exercise training is an evidence-based adjunct treatment for patients with HF (35,41,42).…”

Section: Discussionmentioning

confidence: 99%

“…We recently demonstrated that LVAD implantation normalizes CBF at rest but fails to compensate during exercise compared with age-matched healthy controls and patients with HF (37). In healthy individuals, the exercise CBF-response follows a biphasic pattern of initial vasodilation during submaximal exercise, followed by a plateau (9,31,38).…”

Section: Discussionmentioning

confidence: 99%

“…However, relatively little is known about the impact of LVAD implantation on cerebral blood flow during exercise in this group. Despite the observation that LVADs normalize cerebral blood flow (CBF) at rest (11,34,37), we recently reported no observable increases during incremental exercise (37). This impairment may be ameliorated if pump speed is progressively increased in conjunction with exercise intensity (8).…”

Section: Introductionmentioning

confidence: 91%

“…The relative lack of cerebral hyperemia during exercise may be related to a lack of reflex increase in cardiac output (8) as well as the absence of an increase in intracranial vasodilation due to impaired shear stress and the lack of pulsatility (40). Cerebrovascular dysfunction during aerobic exercise in HF that persists despite LVAD implantation (7,8,37) may have potential long-term implications for brain function and health.…”

Section: Introductionmentioning

confidence: 99%

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Cerebral blood flow responses to exercise are enhanced in left ventricular assist device patients after an exercise rehabilitation program

Smith

Moreno-Suarez

Scheer

et al. 2020

Journal of Applied Physiology

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Cerebral blood flow during exercise is impaired in patients with heart failure implanted with left ventricular assist devices (LVADs). Our aim was to determine whether a 3-mo exercise training program could mitigate cerebrovascular dysfunction. Internal carotid artery (ICA) blood flow and intracranial middle (MCA v) and posterior cerebral (PCA v) artery velocities were measured continuously using Doppler ultrasound, alongside cardiorespiratory measures at rest and in response to an incremental cycle ergometer exercise protocol in 12 LVAD participants (5 female, 53.6 ± 11.8 yr; 84.2 ± 15.7 kg; 1.73 ± 0.08) pre- (PreTR) and post- (PostTR) completion of a 3-mo supervised exercise rehabilitation program. At rest, only PCAv was different PostTR (38.1 ± 10.4 cm/s) compared with PreTR (43.0 ± 10.8 cm/s; P < 0.05). PreTR, the reduction in PCAv observed from rest to exercise (5.2 ± 1.8%) was mitigated PostTR ( P < 0.001). Similarly, exercise training enhanced ICA flow during submaximal exercise (~8.6 ± 13.7%), resulting in increased ICA flow PostTR compared with a reduced flow PreTR ( P < 0.001). Although both end-tidal partial pressure of carbon dioxide and mean arterial pressure responses during incremental exercise were greater PostTR than PreTR, only the improved [Formula: see text] was related to the improved ICA flow ( R2 = 0.14; P < 0.05). Our findings suggest that short-term exercise training improves cerebrovascular function during exercise in patients with LVADs. This finding should encourage future studies investigating long-term exercise training and cerebral and peripheral vascular adaptation. NEW & NOTEWORTHY Left ventricular assist devices, now used as destination therapy in end-stage heart failure, enable patients to undertake rehabilitative exercise training. We show, for the first time in humans, that training improves cerebrovascular function during exercise in patients with left ventricular assist devices. This finding may have implications for cerebrovascular health in patients with heart failure.

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Section: Discussioncontrasting

confidence: 56%

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 91%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Cerebral blood flow responses to exercise are enhanced in left ventricular assist device patients after an exercise rehabilitation program

Smith

Moreno-Suarez

Scheer

et al. 2020

Journal of Applied Physiology

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Feasibility of high‐intensity interval training in patients with left ventricular assist devices: a pilot study

et al. 2020

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Aims Patients with left ventricular assist device (LVAD) suffer from persistent exercise limitation despite improvement of their heart failure syndrome. Exercise training (ET) programmes to improve aerobic capacity have shown modest efficacy. High‐intensity interval training (HIIT), as an alternative to moderate continuous training, has not been systematically tested in this population. We examine the feasibility of a short, personalized HIIT programme in patients with LVAD and describe its effects on aerobic capacity and left ventricular remodelling. Methods and results Patients on durable LVAD support were prospectively enrolled in a 15‐session, 5 week HIIT programme. Turndown echocardiogram, Kansas City Cardiomyopathy Questionnaire, and cardiopulmonary exercise test were performed before and after HIIT. Training workloads for each subject were based on pretraining peak cardiopulmonary exercise test work rate (W). Percentage of prescribed training workload completed and adverse events were recorded for each subject. Fifteen subjects were enrolled [10 men, age = 51 (29–71) years, HeartMate II = 12, HeartMate 3 = 3, and time on LVAD = 18 (3–64) months]. Twelve completed post‐training testing. HIIT was well tolerated, and 90% (inter‐quartile range: 78, 99%) of the prescribed workload (W) was completed with no major adverse events. Improvements were seen in aV̇O2 at ventilatory threshold [7.1 (6.5, 9.1) to 8.5 (7.7, 9.3) mL/kg/min, P = 0.04], work rate at ventilatory threshold [44 (14, 54) to 55 (21, 66) W, P = 0.05], and left ventricular end‐diastolic volume [168 (144, 216) to 159 (124, 212) mL, n = 7, P = 0.02]. HIIT had no effect on maximal oxygen consumption (V̇O2peak) or Kansas City Cardiomyopathy Questionnaire score. Conclusions Cardiopulmonary exercise test‐guided HIIT is feasible and can improve submaximal aerobic capacity in stable patients with chronic LVAD support. Further studies are needed on its effects on the myocardium and its potential role in cardiac rehabilitation programmes.

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ln silico simulation of the interaction among autoregulatory mechanisms regulating cerebral blood flow rate in the healthy and systolic heart failure conditions during exercise

Bozkurt

Ayten

2022

Med Biol Eng Comput

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Cerebral Blood Flow during Exercise in Heart Failure: Effect of Ventricular Assist Devices

Abstract: The results of the study are presented clearly, honestly, and without fabrication, falsification, or inappropriate data manipulation, and statement that results of the present study do not constitute endorsement by ACSM.

Cited by 15 publications

References 32 publications

Cerebral blood flow responses to exercise are enhanced in left ventricular assist device patients after an exercise rehabilitation program

Cerebral blood flow responses to exercise are enhanced in left ventricular assist device patients after an exercise rehabilitation program

Feasibility of high‐intensity interval training in patients with left ventricular assist devices: a pilot study

ln silico simulation of the interaction among autoregulatory mechanisms regulating cerebral blood flow rate in the healthy and systolic heart failure conditions during exercise

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